1. Field of the Invention
The present invention relates to data communication between a user's apparatus and another apparatus, such as the access from a terminal on the Internet to a Web site. More particularly, the present invention relates to a technique of facilitating the handling of personal information of each user and enhancing the security of the personal information.
2. Description of the Related Art
In recent years, the Internet has become increasingly popular, and more and more services are being provided on the Internet. A major service offered on the Internet is the World Wide Web (WWW), which is a client/server-type information search system. In the WWW, server apparatuses (Web sites) provide information in HTML files and users of the Internet browse the information using browsing software called Web browsers at terminals (Web clients) Various information and services are currently provided at numerous Web sites, and a technology called “cookies” is widely used to provide information with efficiency. When a user enters a Web site) the Web site stores data, such as personal information of the user, as a cookie in the terminal of the user through the Web browser. The next time the user goes to the same Web site using the same terminal, the Web site reads the cookie from the terminal and uses the read cookie to provide information to the user.
Cookies usually show personal information of users, the last dates and times the users visited Web sites, and the numbers of times the users have visited the Web sites. Cookies are also used to identify users. Therefore, cookies are used as an element of technology in various authentication systems and personalizing systems that customize services provided in the WWW for respective users and provide the customized services to the users.
While being a useful technology, cookies also have the following problems. One problem is that Web sites store data, such as personal information of users, into terminals with which the users visit the Web sites. If a single user uses a plurality of terminals or a plurality of users share a single terminal or a plurality of terminals, Web sites cannot correctly obtain and use information of respective users with cookies. Also, if a user replaces an old terminal with new one, data stored as a cookie in the old terminal does not exist in the new terminal. Therefore, to continuously use the cookie even after the replacement of the terminal, the user needs to copy the cookie from the old terminal to the new terminal, which constitutes a burden on the user.
Another problem is that personal information of users may be automatically stored as cookies without the users intending to do so, and even other Web sites, which are not the sites that stored cookies, may refer to the cookies with relative ease. Consequently, there may be cases where cookies are maliciously read, causing user's privacy to be violated or making users a victim of cyber fraud. This generates demand for the enhancement of the security of personal information.